Phosphoric acid as used analytically as a reagent chemical and is used commercially in a wide variety of processes, syntheses and operations. It is used as an acidulant in many chemical processes which require control of pH, for example, to control the pH in chemical reactions, in foods and in animal feeds.
Phosphoric acid is available commercially in liquid form typically in two strengths, 75% solution having a phosphorus content of 23.7% by weight and 85% solution having a phosphorus content of 26.8% by weight.
Due to the highly acidic nature of phosphoric acid solutions, all transport, storage and handling equipment using it must be of the type that is not susceptible to attack by the phosphoric acid, typically, either glass lined or stainless steel equipment. Also, great care must be used in handling it, lest the acid come in contact with some acid-vulnerable substances.
Moreover, since commercial phosphoric acid is very heavy (specific gravity 1.7 (85% solution) and is in aqueous solution, transportation costs are quite high, as the ultimate consumer must pay the additional cost of transporting the water in solution which does not normally contribute economically to the process in which the phosphoric acid is used.